January 18, 1562: The counter-reformation Council of Trent reconvenes after a 10-year break caused by the revolt of Protestant princes against Emperor Charles V. During the break, all hope of reconciliation between Catholics and Protestants had vanished.
January 18, 1815: Konstantin von Tischendorf, the biblical critic known for discovering and deciphering the "Codex Sinaiticus" (a fifth-century manuscript of Paul's epistles), is born in Germany.
January 18, 1830: Baptism of Tauta'ahau Tupou. King of Tonga by a western missionary. Beginning of a strongly missionary Christian Kingdom.